Method of and means for drying lumber



' Nov. 19, 1929. M. L; MIJ ELLER METHOD OF AND MEWS :fioR DRYING LUMBER Fiieq AiigiQ- ZZ, 192a 2 Sheets-Sheet 1- lll lll itll Nov.

. M. L. MUELLER METHOD OF AND MEANS FOR DRYING LUMBER Filed Aug. 22, 1928 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY} Patented Nov. 1%, 1929 U- NITE D sTA T E sf PAT- vronrrz L; MUELLER, or SEATTLE, tinesniiss'reiu; Assisnon; To; ii -oitrnwnsr ilion nit nit-ii cc vrranm orroitrtann, censors, AICORPORATION, F..;w sHmGroW 'iivrnrlaon or Ann Means FOB DRYING LUMBER" App lication filed August a2, 1928. SeriaLNo. 301,324.

'This invention relates to a method of and means for 'drylng lumber and more partlcularlyto' the drying of flat piledlumber. The

drying of lumber whenpiled flat presentsv a diificult problem. It-is usually piled in units (loads), the edges of which forman even Spacersare used between the several courses of lumber so that below the vedge of line.

each course there is a space for theentrance of air which conducts heat to the material.

andconducts moisture away from it.

One of the important objects of the present invention is to so direct, adjust and control the flow of the air as to cause all of. the vari-A 5" ous courses 01 the material-to dry at an even rate. This is desirable in order to prevent part of the lumber lagging behind in its'drying after the balance is finished. It is addi-E tionally desirable because the rate of air flow controls the quality ofthe dried stock.

Broadly stated the invention resides in di-. recting the drying air atsuch an angle with respect to-the vertical side of the pile of lumher that theoverhanging'edges oi the several courses catch theair and 'direct'it by a deflect ing action through the various channels be tween the-courses of the lumber.

The invention further resides in so direct. ing and controlling the air currents that substantially all parts of the pile will receive the same treatment The invention further contemplates the provision of means for-reversing thedirection of current flow, in combination with the angular discharge of the air toward the pile of lumber, as above set forth. By'virtue of this reversal of current flowand the blowing v of the air into the material'first from one direction and then from the other I avoid the necessity for a high degree of'refinement and accuracy of the air control and am able to sei combined novel deflectors therewith "'in jsuchf I cure all necessary practical results with much used to secure the above described results, that air surrounding-the movingair stream will be induced to enter the stream, thus givinga larger total air flow than that set up by the air circulating medium's fhereinafter deright toleft;" 1

strips 10,"the"result beingto leave the-pile:

scribed- This saves power, inas itch standard equipment of small capacity can be I made to produce abnormallylarge air move- 3 ments in a'closed circuitairlstream. I In the accompanying drawings, "which are merely illustratlve of the -princlpleslmyolved g in thepresent invention;- a .i Fig. 1 s a d agrammatic transverse sectional view through a lumber drying kilnj the air flow through the lumber bein'g' fronr Fig. 2 is av iew like Fig. 1 but with the de flectors adjusted to set upa circulation of air frornleft to right, through-the lumber Flg. 3 atransyer se vertica'l Z sectional viewthrougha lumber drying kiln ill'u'strating, a modified arrangement I ofideflectorsfi f Fig. leis-a iew' imilar to Fig. 3' modified to? illus tratea circulating fan; I

F1g. 5 is an enlargedsectional View througli T a portion of the edge of one "of the lumber p les, and i i Fig. 6 is a diagrammatic view, hereinafterdescribed. I l;; Referring now to the drawings andmor particularly to Figs. 1" and ,2; 5 designates a lumber drying kiln? ofa conventionalitype provided with track; rails 6 upon' which lumber trucks; 7 maybe run into the-kiln; pile-10f? lumberto bedried 'isindicated at 8 T'he-S M courses of the lumber indicated at Qfare' spaced from each other-bytransversespacing lumber honey-combed with 1 a multiplicity f transverse channels 'lll.1 It is' common practice 'inthehmber "dlylfig i art to locate a longitudinally extending pressure duct l2iand longitudin ally e-Xtending suc tion ducts 18 in the lower portionof-lumber i dryingkilns and'I have utilizedsuch an arrangement in the present inyention butjha've in Fig; 2'." With'th'e' deflector lt setinthe" position illustrateddn 1 'and w 'ith the dampers or-closures 16 of the left hand su'e- 12 being discharged upwardly -will becaught by the deflector 14 and deflected :toward the. right hand'side of the kiln. A series of curved deflectors 18, 18?, 18 catch the air and direct it upwardly and inwardly; in such manner that it strikes the vertical'side of the pile of lumber at varying points in the height of the pile. In other words the air is distributed substantially uniformly over the entire side.

of the pile of lumber throughout the height of said ile.

2O edges of said deflector, thus drawing into the air stream air from the lower portion of the kiln that would not otherwisebe drawn :into

- the air stream. The air that is dischargedpast the deflectors 18, 18, 18 at an acute; angle toward the side of .thelumber'pile is caught by the overhanging edges 19 (see Fig. 5) of theseveral courses of lumber and directed through the channels .11 asindica-ted by the arrows.- At the lower left hand side of the. V g kiln a part of this air is drawn into the suctionduct 13, returning; to. the air stream through the pressure duct 12 'in amanner' quite common in lumber dr-yingkilns;

The structure illustrated in Fig. 2is like 'g fthat illustrated in Fig. 1 except that the V deflector 14 hasbeentipped upon its hinge ct ta or pivot 15 in such manner that air discharged out of the top of thepressure duct 12 is caused to travel toward the left. damper 17 of the right hand suction duct is open and the damper-'16 of the left hand suction duct is'closed. The flow of the air will then be. as 'indicated'bythe arrows past deflectors 18, 18- and-18. The same injector tor114. 7

In;Fig- 3-the arrangement of parts is the same except that deflectors 18, 18 18 and 18, 18?, 18? aresubstitutednfor thecorresponding deflectors of Figs. 1 and 2. These latter de vflectors instead of being in two groupsin sub-' stantially the same horizontal plane are dis- I posed atvarying points in the heightof the IV In Fig. .4. a fan 20 is1nsed as the circulat; ing medium in lieu ofthepressure and suction duct and-jinthis case reversal of current flow is? secured by reversing the direction of rotation of the fan. In, this form of the inventiongroups of diffusion deflectors 18,

18 are used in conjunction'with the vertically spaced diflusion deflectors 18, 1;8, itbeing noted that the lowermost of these last named deflectors are spaced further from the sidewalls of the kiln than the intermediate I sult.

In this case the place at the edges of the defleo- T ones of said deflectors and that said intermediate deflectors are spaced further from the side walls of the kiln than the uppermost of said deflectors. Consequently dif ferent portions of the vertically moving air stream are caught and deflected at an angle toand beneath the overhanging edges of the several courses of lumber, the result being to supply a substantially uniform quanu pon trucks inthis fashion and to deliver air from below or above the space between The ow of air to the right from the de-. flector 14 creates an injector action at thev constricted openings Z at the lower and upper therlumber and the kiln wall in such manner that the air travels in a vertical direction. The problem has. been to cause this vertical air current to be diffused evenly into horizontal air spaces exceeding 111 total area the throat (entrance space) of thedistributing chamber. 7 r

' Heretofore baffles have been used to close this chamber so that by stopping the natural with the result that there is a difference in thevolume of air passing between the upper and lower parts of the loads.

The principles of deflection and diffusion,

however, may be used to overcome this re- Air flow, like light, follows certainlaws of deflection and diffusion. Air strilc.

ing an obstruction at an acute angle leaves the obstruction at an equivalent angle. A

stream of air diffuses in a cone shaped stream, the side angles of which in; relation tothe average direction, are acute in proportion to the velocity, momentum and other setf characteristics of the air. 1 I propose by the use of various deflectors rapidly in most cases away from such point" to control the air flow from any source in v such manner as to produce the proper angle 7 in relation to the, edge of the load, required to distribute the air evenly into such load, it being apparentthat a constant angle will produce even distribution. i

The" reversing deflector l l may be setto other thanitsrextreme position. This deflector not only reverses the air flowbut it also serves, by a proper adjustment, to con-.

trol the angle at which the air stream strikes the kiln wall or the other deflectors. 4 A sharperarc or a stronger pitch of this deflector may raise or lower the air stream. The

secondary deflectors located at the juncture of the air stream with its first obstruction (the wall atthe rail line), or in thevertieal space between the load and the wall, or in v both places, controls the; angular travel of The full line 'arrows'in thisifigure show how the air may be deflected directly from thethe airthrough deflection and the 'shape'of diffusion ofthe 'air' stream by obstruction- The number and location offthe deflectors may be varied at will, thisbeingwgovernedi by the load, spaces, dimensions tetcainsindividual cases. i :1

Fig. 6 isarliagrammatic view of a mod-' ified form, wherein the pressure duct'12 and the. suction ducts l6 16 have flat tops.

deflector 14 against the side wall-of the. kiln and'ithence to the edgesi of the lumber at one point, while the dot and dash arrow in- ;dicate how, with the deflector set in another position, the air may be deflected first against the flat top of the suction duct, thence to the side wall of the kiln and thence against the edges of the lumber at a different point.

The use of this arrangement renders it posniechanism, but that it includes within its sible to dispense, in some constructions, with the side deflectors, and is of importance.

It is to be understood that the invention is not limited to the use of any particular purview whatever changes fairly come within either the terms or the spirit, of the appended. claims.

Having described my invention what I claim is:

1. The combination with a kiln, and means for settlng up a circulatlon of air transverse 'ly thereof, of deflecting means at each side of the kiln comprising a group of horizon-- tally spaced deflectors adjacent the lower portion of each side wall of the kiln, a centrally arranged pressure duct discharging air upwardly, and a pivoted deflector above the pressure duct arranged to direct the air discharged therefrom to either of said groups of deflectors.

2. The combination with a kiln, and means for setting up a circulation of air transversely thereof, of deflecting means at each side of {the kiln comprising a group of horizontally spaced deflectors adjacent the lower portion of each side wall of the kiln, a centrally arranged pressure duct discharging air upwardly, and a pivoted deflector above the pressure duct arranged to direct the air discharged therefrom to either of said groups of deflectors, suction ducts at each side of the kiln and independently operable closures for the ports of each of saidsuction ducts.

3. The combination with a kiln and means for setting up a circulation of air transverse- 1y thereof, comprising a .centrally disposedlongitudinally extending pressure duct, said pressure duct discharging air upwardly from oo the top thereof,of deflecting means in the kiln arranged to direct the air between the side wall of the kiln and the pile of lumber, and deflecting means comprising an arcuate deflector mounted for tilting movement above ca the pressure duct, said arcuate deflector dipressure pressure duct discharging air upwardly from thetop thereof. of deflecting means'in the.

' kiln: arranged to direct-the air between the? I side wall of the kiln and the pile of ilumbery and'ideflect'ingmeans comprising. an arcuate deflector mounted for tilting-:5 movement above thepressure duct, and in suchspaced relation thereto as topermit the drawing of induced air: into the air stream fr0m the "suction side of said deflector. r1 i -5. -'The-combination with a'kiln, a v d means forsettingup a circulation of air:transverse-J lyv thereof, of deflecting meansin'the 'kil-n' ar-' ranged to direct the air" currents against the vertical sides of piles of lumber, flat 'piled in spaced courses at such angles th'at the edges i of said courses catch and. deflect the'aircurs rents through the channels .betweeniwsaid courses, substantially throughout the entire height of said piles, vthe means for setting up a circulation of: air in the kiln comprising a centrally arranged pressure duct 'and-suctioni ducts upon'oppo site sidesythereoflsaid'sucy tion' ducts' being located substantially. be-1. neath the spacebetweenithe side wall of the kiln-and the. ipile'ioif lumber, and. an: arcuate deflector mounted "-for .tilting: movement i abovethe pressure duct and adapted todirect' .370 longitudinally extending pressure duct, said deflectors at the' lower end'offthe'space between the piles of 'lumberin the-kiln and the side walls ofithe kiln, the several deflectors being of such'size'and shapeas to direct a plurality: ofstreams-of air against: the sides of;the;p'i1es of lumberatvaryingpointsin the" height thereof; sothat when said streams are i discharged-"against" the piles of lumber,' flatpiled in='-spaced courses, the exposed lower. edges of said courses catch and deflect the air currents through the channels between saith courses, a centrally arranged pressure duct, andfa movable deflectormounted for tiltingmovement thereover' to? varythe direction or air flow .toward the horizontally spaced group ofideflectorslza f f 2 7 7. Thecombination with an kiln and means 1 for setting up a'circulation of air transverse ly-=thereof, a plurality of'sets of deflecting means in. the kiln attach side of {said kiln, andsub'stantially beneath tlie spaces between the side walls of tthe"'kiln, and'piles-of lumber flat piled in spaced courses .in :said kiln, said deflecting means "being fdisposedfatfsuch angles. and-tin. such positions, with respect t0j--- entire height thereof and at such angles that the overhanging edges of said courses of lumber catch and deflect the, air currents through the channels between said courses, substantially throughout the entire height of said piles, a centrally arranged pressure duct be 7 neath the lumber piles, and a tiltable'deflector above the pressure duct, serving to direct the aircurrents therefrom to either one or the other of said sets of deflecting means;

8. The combination with a kiln and means forsetting up a circulation of air transverse ly' thereof, a plurality of sets of deflecting means in the kiln at each side of said kiln, and substantially beneath the spaces between;

the side walls of the kiln, and piles of lumber flat piled in spaced courses in said kiln, said deflecting means being disposed at vsuclr angles and in such positions, with respect to each other and with respect to the piles of lumber, as to direct the air currents against" I the verticalsides of said-lumber piles, at

varying points substantially throughout the entire height thereof and at such angles that the overhanging edges of said courses of lum- V 30 her catch and deflect the air currents through the channels between said courses, substan tially throughout the entire height ofsaid' piles, a centrally arranged pressure ductbee 'neath the lumber piles, and atiltable deflec 1 tor above the pressure duct serving to direct I theair currents therefrom, to either one or the other of said sets of. deflecting means, said deflector being mounted in such spaced relation to the pressure duct as to permit the drawing of induced air into the air stream from the suction side of said deflector 9. The combination with a kiln and means for setting up a circulation of air transverse ly thereof, of deflecting means inthe kiln ar- 1 ranged to direct the air currents against the vertical sides of piles of lumber, flat piled in spaced courses at such angles that the edges 7 of said courses catch and deflect the air currents through the channels; between said courses, substantially throughout the'entire height of said piles, the means forsetting up" such circulation ofair in the kiln comprising a centrally arranged pressure duct and a group of deflectors lying beneath the space between the pile of lumber and the side wall of the kiln, all of said deflectors being dis- I posed in substantially the same horizontal plane, and the several deflectors being dis posed in such positions andat such angles and presenting such surfaces'that the air discharged by each deflector will strike the pile of lumber at a point different from that at which the air from any other of said deflectors strikes said pile, said deflectors being spaced from each other to present open chant.

nels between them, and means for directing the air from the centrally arranged pressure 1 duct into thelower ends of the channels between the deflectors. g

10. A, structure as recited in claim 9,-

wherein the means for directing the air from the centrally arranged pressure duct to the horizontal group of deflectors comprises a deflector located. above the pressure duct and horizontal 

